Hello everybody. For years I’ve been attending an everlasting discussion between my wife and a friend of her. Everytime coffee is served the same conversation is repeated. My wife claims that coffee will cool faster if you remove the spoon, while her friend argues that the heat will go through the metal and into the air, so he says it is better to keep it in the cup if you want it to cool. As none of them is exactly an expert scientist, and both are stubborn as they can be, the conversation goes on and on. Please, release me from this torture.
F.Zurita. Córdoba, Spain. :smack:
Given that the specific heat capacity of water is far greater than the metal of the sppon, it won’t make much difference, really. But, leaving the spoon in should VERY slightly increase the rate of cooling by increasing the total heat-radiating surface area. Might make a noticeable difference if you stuck in a number of spoons. I suggest an experiment.
What he said.
If this is a serious problem, though, just drop in an ice cube. Or a frozen cube or cream, maybe.
My parents once had an aluminum cylinder for coffee cooling. They kept it in the freezer, and setting it in a cup of coffee would cool it down in a hurry without diluting the coffee.
I just use an ice cube, myself, and I make the coffee a little stronger to compensate for the dilution.
I’m with the ice cube crowd. Some call it heresy. I call it no burned tongue.
The amount of heat the spoon is transmitting out is going to be directly proportional to the temperature of the handle. Since the handle of a stainless steel spoon is likely to remain pretty cool in comparison to the coffee, I doubt it transmits much out. A silver spoon would transmit more heat, it’s a better conductor, a plastic spoon, worse. Ultimately, I agree with QED, the effect would be pretty negligible.
However, if your goal is to cool down the coffee, and your only tool is the spoon, you should leave the spoon in, and STIR the coffee. Agitating the liquid will help cool it down a lot better than just leaving the spoon in and relying entirely on convection currents to mix the temperature layers.
The heat in coffee basically has 3 places to go: air, cup, spoon. The spoon is one place extra for the heat to go, and has the bonus of helping it get to the air slightly more effectively. But the cup is the most effective heat sink in this scenario.
The best way for the sensitive-tongued to cool a cup of coffee is to transfer it into a second cup. It will then be easily drinkable (if not a tad on the cool side) provided the second cup hasn’t already been heated in some way. Alternately, serve the wimp’s coffee in a heavier mug than everyone else.